package com.leetcode.Offer;

public class JZ25 {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        //回调
        if (l1 == null) {
            return l2;
        } else if (l2 == null) {
            return l1;
        }

        ListNode head = null;

        if (l1.val < l2.val) {
            head = l1;
            head.next = mergeTwoLists(l1.next, l2);
        } else {
            head = l2;
            head.next = mergeTwoLists(l1, l2.next);
        }
        return head;
    }
}
